Question

Find the inverse of A = [ 1 2 3 −1 1 2 1 2 4 ] by adjoint method.​

Answer 1

Step-by-step explanation:

|A| = 1(4-4) -2 (4-2) + 3 (2-1)

= 1(0) - 2(2) +3(1)

= 0 -4 +3

= -1

adj A = cofactor of A'

= 0 2 1

2 1 -1

1 0 -1

A-¹ = 1 [ 0 2 1

-1 2 1 -1

1 0 -1]

May it helps you.